Add ability to get JPad rules count

[OrRosenblatt]

Add support to get JPad rules total count when passing JPad file or providing JPad url.

Suggested solution:
NPM client that will provide some utils functionality for JPad files.

[nataly87s]

Add jpad-tools npm package.
it should expose a getRulesCount method that gets a jpad and returns the rules count

[nataly87s]

We will add a package in the future, for now you can use this:
npm i --save get-jpad-rules-count@gist:644f317d3b73144f1bc17c44cadab3b7
or
yarn add get-jpad-rules-count@gist:644f317d3b73144f1bc17c44cadab3b7